Add case study: Booking.com (#20783)

* Create index.html

* add logos

* fix logo file name

* add booking.com images

* remove Nav from featured

* add booz allen featured logo

* make Booz Allen featured

* remove spotify from featured

* fix booz allen front matter

* add correct logo

* add correct booz allen logo

content/en/case-studies/nav/index.html

@@ -5,11 +5,7 @@ linkTitle: Nav
 case_study_styles: true
 cid: caseStudies
 css: /css/style_case_studies.css
-logo: nav_featured_logo.png
-featured: true
-weight: 3
-quote: >
-   The community is absolutely vital: being able to pass ideas around, talk about a lot of the similar challenges that we’re all facing, and just get help. I like that we’re able to tackle the same problems for different reasons but help each other along the way.
+featured: false
 ---
 
 <div class="banner1" style="background-image: url('/images/CaseStudy_nav_banner1.jpg')">